18,666 research outputs found
Analysis of the decays induced from SUSY loops within the Mass Insertion Approximation
In this paper we study the lepton favor violating decay channels of the
neutral Higgs bosons of the Minimal Supersymmetric Standard Model into a lepton
and an anti-lepton of different flavor. We work in the context of the most
general flavor mixing scenario in the slepton sector, in contrast to the
minimal flavor violation assumption more frequently used. Our analytic
computation is a one-loop diagrammatic one, but in contrast to the full
one-loop computation which is usually referred to the physical slepton mass
basis, we use here instead the Mass Insertion Approximation (MIA) which uses
the electroweak interaction slepton basis and treats perturbatively the mass
insertions changing slepton flavor. By performing an expansion in powers of the
external momenta in the relevant form factors, we will be able to separate
explicitly in the analytic results the leading non-decoupling (constant at
asymptotically large sparticle masses) and the next to leading decoupling
contributions (decreasing with the sparticle masses). Our final aim is to
provide a set of simple analytic formulas for the form factors and the
associated effective vertices, that we think may be very useful for future
phenomenological studies of the lepton flavor violating Higgs boson decays, and
for their comparison with data. The accuracy of the numerical results obtained
with the MIA are also analyzed and discussed here in comparison with the full
one-loop results. Our most optimistic numerical estimates for the three neutral
Higgs boson decays channels into and leptons, searching for their
maximum rates that are allowed by present constraints from data and beyond Standard Model Higgs boson searches at the LHC, are
also included.Comment: 37 pages, 16 figures, 3 appendices. This version v3 matches the
manuscript published in JHE
Tracing the spiral arms in IP Pegasi
We report the analysis of time-resolved spectroscopy of IP Pegasi in outburst with eclipse mapping techniques to investigate the location and geometry of the observed spiral structures. We were able to obtain an improved view of the spiral structures with the aid of light curves extracted in velocity bins matching the observed range of velocities of the spiral arms combined with a double default map tailored for reconstruction of asymmetric structures. Two-armed spiral structures are clearly seen in all eclipse maps. The arms are located at diïŹerent distances from the disc centre. The âblueâ arm is farther out in the disc (R = 0.55 ± 0.05 R L1 ) than the âredâ arm (R = 0.30 ± 0.05 R L1 ). There is evidence that
the velocity of the emitting gas along the spiral pattern is lower than the Keplerian velocity for the same disc radius. The discrepancy is smaller in the outer arm (measured velocities 10â15 per cent lower than Keplerian) and is more significant in the inner arm (observed velocities up to 40 per cent lower than Keplerian). We measured the opening angle of the spirals from the azimuthal intensity distribution of the eclipse maps to
be Ï = 25⊠± 3⊠. A comparison with similar measurements on data at diïŹerent outburst stages reveals that the opening angle of the spiral arms in IP Peg decreases while the outbursting accretion disc cools and shrinks, in agreement with the expected evolution of a tidally driven spiral
wave. The sub-Keplerian velocities along the spiral pattern and the clear correlation between the opening angle of the spirals and the outburst stage favors the interpretation of these asymmetric structures as tidally-induced spiral shocks
CIVIC LIFE: Evidence Base for the Triennial Review
This document forms part of the Equality and Human Rights Commission triennial review and covers equalities in civic life. It examines equality in political participation, freedom of language and freedom of worship. The primary aim is to map the various dimensions of equality and inequality in participation in civic and political life. We explore and review equalities, good relations and human rights in relation to civic life, and where possible we examine some of the driving forces behind the differences that we observe
Unification of SU(2)xU(1) Using a Generalized Covariant Derivative and U(3)
A generalization of the Yang-Mills covariant derivative, that uses both
vector and scalar fields and transforms as a 4-vector contracted with Dirac
matrices, is used to simplify and unify the Glashow-Weinberg-Salam model. Since
SU(3) assigns the wrong hypercharge to the Higgs boson, it is necessary to use
a special representation of U(3) to obtain all the correct quantum numbers. A
surplus gauge scalar boson emerges in the process, but it uncouples from all
other particles.Comment: 12 pages, no figures. To be published in Int. J. Mod. Phys.
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